The Swifts 



bluish spot at their base and are tinged with red at their margin. 

 Those of the sides are more finely spotted (speckled) with these 

 colours. The limbs and tail are usually of a rich, blue tint. Al- 

 together the effect is that of a stained glass window, in miniature. 

 The greater portion of the abdomen is greenish-blue. 



Distribution. — Mountain regions near the coast of south- 

 western California. 



Sub-division 1 1 of the first group of Spiny Swifts, contains 

 but one species (north of Mexico). It differs from the preceding 

 in having the inner margin of small scales completely border- 

 ing the crescentic margin of the supraocular plates. There is a 

 single row of external scales with the majority; occasional spec- 

 imens have fragmental indications of a second row. 



The Spiny Swift, Sceloporus spinosus, (Wiegmann), is one 

 of the large species. The scales are large, strongly keeled and 

 terminate in very pronounced, spiny points, presenting a decidedly 

 bristling aspect. 



Dull olive or grayish, sometimes greenish or yellow; a series 

 of narrow, wavy, black cross-bands on the back, continued in 

 closer formation on the tail, in ring-like fashion. On each side 

 of the back, but particularly distinct upon the shoulders, is a 

 pale band, the width of a single row of scales and a half row on 

 each side. Male specimens have a large, oblong, black patch 

 near the region of each shoulder. The abdomen of the male 

 is marked on each side with a large purple blotch, margined 

 with black; little or no blue on the under surface of the female, 

 and on neither sex is there an indication of a black collar. 



Dimensions. — Total Length 9J inches. 



Length of Tail 5.V " 



Width of Body li " 



Width of Head i' " 



Distribution. — Abundant in Mexico and extending north- 

 ward, and commonly, throughout western Texas and New Mex- 

 ico. As far east as Dallas it becomes rare, but the distribution 

 in the United States is continued eastward to Pensacola, Florida. 



Habits. — The Spiny Swift lives most frequently upon the 

 trunks of trees, mostly on fallen timber, over which it runs 

 with an amazing show of speed. Friends of the writer, who 

 have collected the species in Mexico, tell him that it ascends the 

 trunks of trees with a great alacrity until a short distance over 



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